Thursday, 20 July 2017

Turning Fine-Tuning on its Head

The existence of you and m e is, in a sense,
fine-tuned. This statement might come as
a surprise to anyone who has noticed that I am vehemently against the
fine-tuning argument, but I can explain.
The fine-tuning argument goes a little like this:

Fine-tuning,

Therefore, god.

I've stripped it down a bit, but those are the basics of the
argument. I don't have much against the
first line, but I do have problems with the second as I would have problems
with the first premise of an expanded fine-tuning argument, namely the
assertion "If fine-tuning then god".
The stripped-down deluxe version of the argument, which I also have
problems with, is:

If there is fine-tuning, then
either god or something else,

Fine-tuning,

Not something else,

Therefore, god.

My problem is with the third line of this version. When argued by such luminaries as WLC the
main thrust is that the idea that we should be here purely by chance,
when the odds against are so staggeringly high, beggars belief. The problem is that there remains a gap
between unlikely and impossible. The
answer "something else" remains possible, and to some it is
believable despite being unlikely, while the god solution is simply not
believable.

What I don't argue against is the line
"Fine-tuning", so long as that line is short-hand for "if things
were slightly different in this universe, then intelligent life would almost
certainly not exist". If
"fine-tuning" is short-hand for "this universe was designed by a
divine being of some sort", then of course I have a problem but then the
whole fine-tuning argument resolves down to begging the question, "god,
therefore god".

Now, about you and me being fine-tuned - let's get all
excited about it! Think about how amazing
it is that we exist on one little planet in such a massive universe. What are the chances of that? If we go by volume, we can see that the Earth
is only about 10-56 of the observable universe's volume. If we were just about anywhere else, we'd be
dead.

But of course it'd be silly to compare our location with a random
spot in intergalactic or even interstellar space. It's pretty cold out there, and we need to be
a bit warmer than that, without being too warm.
So we could consider how remarkable it is that we are in orbit around
just this star, one that is so suitable for intelligent life to develop. While our sun is one of about 1021
stars, it's a pretty common type of star - roughly one in five is a G-class
star. And about one in five of those is estimated to have an
"Earth-like" planet in orbit around it - in the habitable zone. So about one in twenty-five stars are of the
right type with the right type of planet in orbit around it.

Not that amazing after all.
Although, to get the one in twenty-five figure we are assuming that once
we've got the right type of star, and it's got the right sort of planet in the
right sort of zone, then we get that one automatically. That's a little unreasonable. Our solar system is jam-packed with planets,
moons, asteroids and comets (by which I mean generally "very sparsely
packed, but with more than half a million objects"). The
chances of ending up on the one habitable object out of all of those is about,
well, one in half a million (after we've select the right star, with the right
planet in orbit around it).

If we did limit ourselves to a suitable planet in orbit
around a suitable star though, the fact is that we are on a very privileged
part of that planet - standing somewhere close to the surface (ISS residents
aside, plus anyone currently on a high-altitude international flight). We're sitting or standing rather comfortably
on the surface instead of floating high in the atmosphere, floundering at the
bottom of an ocean or being crushed and then burnt to a cinder in the
core. And we live in a community that is
relatively well placed on that surface: not in a volcano crater, not in Death
Valley, not in Antarctica, not just below the summit of Everest. What great fortune! However, only about one sixth of the Earth's
surface is habitable (half of the land mass).

Then there is timing.
This is a rather good time for intelligent life. The planet that we are on has sufficient
oxygen, not too much carbon dioxide, it still retains enough of the ozone layer
that we don't die too quickly of cancer and the temperature is about right -
not too cold that we freeze to death and not too warm that we are constantly
flayed by killer storms or reduced to desiccated husks. We have flowering plants, most importantly
variations of grass that permit large populations to feed themselves, and they
have only been around for about 55 million years, so 1.4% of the time that the
Earth has been a planet. Humans (as Homo
sapiens) have only been around for about 200,000 years, or one thousandth
of one per cent of the age of the Earth.
Genetic research indicates that humanity has gone through a few
bottlenecks, the most recent may have been about 70,000 years ago - meaning
that we were lucky, as a species, to not go extinct at that time.

It's remarkable that we're alive at all. It's in the order of one in a billion, even
aside from all the unlikeliness of one particular human meeting another
particular human and producing a specific human at a specific time (with none of
them being killed by any of the lethal flora and fauna that is abundant on this
planet). So … sure, we're fine-tuned, in
a sense.

---

The thing is that what I have just provided is a continuous
stream of indicators that our universe is not finely tuned for human
life. Our planet is not
finely tuned for human life – there’s a very narrow band geologically and temporally. We are finely tuned to exist in
that very narrow band and the fine-tuned-ness of a biological organism to its environment
is far more elegantly explained by evolution than it is by the introduction of
a creator being.

The bottom line is that fine-tuning is not a challenge to
naturalism or evolution or atheism, the real challenge is to the creationist or
intelligent design theorist to explain why the universe is so unrelentingly
hostile to humanity.